龙川江年输沙率时间序列的小波特征

基于龙川江出口水文控制站小黄瓜园站的长时间序列水文资料,利用小波变换研究了龙川江流域降水量和输沙率时间序列的多时间尺度变化特征和突变特征.研究表明:小黄瓜园站年降水量时间序列具有2a和4a的准主周期;年输沙率时间序列具有2、4、9.5a左右的准主周期;龙川江输沙率年内分配很不均匀,6～10月输沙量占全年输沙量的96.7%,尤其是7、8两个月输沙量占全年输沙量的55.7%;输沙率年内变化和年际变化的高频振荡主要是由降水量变化所致;龙川江泥沙主要来源于中下游地区(占全流域输沙量的94.2%);小黄瓜园站对屏山站泥沙贡献率为1.69%.

Wavelet characteristics of time series for annual sediment discharge of Longchuang River

Based on hydrologic data of long time series about Xiaohuangguayuan hydrometric station of Longchuan River,the multi-time-scale and jump characteristics of precipitation and sediment discharge time series of Longchuan River were studied utilizing wavelet transform. Results show that the annual precipitation of Xiaohuangguayuan station has quasi-prime periods of 2 a and 4 a; the annual sediment discharge has quasi-prime periods of 2 a,4 a,and 9. 5 a. The sediment discharge of Longchuan River distributes unevenly within a year,the amount from July to October accounts for 96. 7% ,particularly in June and August it takes almost 55. 7% . The cause of the changes within a year and high-frequency tremble is due to the changing time of precipitation. The river sediment stems from midstream and downstream of Longchuan River (the percentage is 94. 2% of the total watershed),and the total load sediment of Xiaohuangguayuan station offers 1. 69% of that of Pingshan station.